Shell Programming and Scripting

Hello,

I use a program using an input stream of parameters:
.

Code:

/my_prog.out <parameters.txt

The parameters.txt file has the following structure:

Code:

name
date
number1
number2
system

now imagine i would like to execute several times (>200) this program, but with different sets of number1 and number2. Is there a way to automatize this by making a shell to change these two very parameters into other numbers? I have no idea how to do that. Could anyone help?

for example it would be a script doing something like this:

Code:

for number1=1 to 100
for number 2 = 3 to 7
change myparameters.txt in these two specific field <- dunno how to do that
./my_prog.out <parameters.txt &

many thanks!

Moderator's Comments:

edit by bakunin: please use CODE-tags as required by the forum rules. Thank you.

Direct the input stream to sed. In sed there are provisions to only change the nth line, for instance:

Code:

sed '7 s/X/y/g'

will change all "X"es to "y"s only on the seventh line. Try it out.

I hope this helps.

bakunin

You could also use a here-doc in this fashion:

Code:

for number1 in $(seq 1 100)
do
    for number2 in $(seq 3 7)
    do
        ./my_prog.out <<EOF
name
date
$number1
$number2
system
EOF
    done
done